The diagnosis of metastatic melanoma is often associated with a very poor prognosis. For advanced stage melanoma (AJCC stage ill and IV) the 5-year survival rate is less than 45% and 5%, respectively. We have developed a treatment regimen for advanced stage melanoma patients referred to as Biochemotherapy (BC) and maintenance Biotherapy that consists of multiple biological and chemotherapeutic drugs concurrently. This regimen is unique in that it is highly effective, producing response rates of 50-60% with less toxicity and reduced hospitalization than historical combination therapies. However, a common problem with advanced stage treatment protocols is the early identification of patients who may benefit from the addition of such aggressive therapy. Current methods to assess treatment response are based on conventional imaging techniques and physical examination. Unfortunately, these techniques can be expensive, time consuming, and requires the presence of a substantial tumor volume for deteion, which delays therapeutic initiation and limits their utility as early indicators of disease response. Improvements in methods to monitor patient response are needed to determine therapeutic efficacy early in the treatment course and avoid unnecessary treatment costs and toxicity in non-responder patients. Blood testing offers an easily accessible route to rapidly monitor serial events that may be associated with disease progression and response to therapy, which may be of clinical significance. We have discovered genotypic markers in acellular serum/plasma from melanoma patients as prognostic genotypic markers (PGM) of disease outcome. Assays using multiplex capillary array electrophoreis (CAE) have been developed to assess genotypic changes of specific markers in melanoma patients in serum. These include microsatellite markers with loss of hetrozygosity (LOH) and methylation of CpG promoter regions of specific genes. Our hypothesis is that genotypic markers in serum can be used as PGM for disease outcome and as predictors of response to therapy early in the course of patient treatment. The novelty of this approach is that serial bloods can be collected during therapy and assessed for both types of PGM. In the R21 phase, the two PGM assays will be established for high throughput, specificity, robustness, reproducibility, and sensitivity. The R33 phase will focus on validating the PGMs and determining their clinical utility in an ongoing prospective multicenter Phase II BC and maintenance Biotherapy trial for AJCC stage IV melanoma patients.